Re: [PATCH 01/13] RDMA: Split the alloc_hw_stats() ops to port and device variants

[Jason Gunthorpe <jgg@nvidia.com>]

On Tue, May 18, 2021 at 09:58:28PM +0000, Saleem, Shiraz wrote:
> > Subject: Re: [PATCH 01/13] RDMA: Split the alloc_hw_stats() ops to port and
> > device variants
> > 
> > On Tue, May 18, 2021 at 12:18:13AM +0000, Saleem, Shiraz wrote:
> > 
> > > > What does the sysfs look like? Aren't there duplicated HW stats?
> > >
> > >
> > > Yeah it is duplicated. So we are saying for phys_port_cnt = 1, we want
> > > the stats to show up in only place?
> > 
> > Yes.
> > 
> > Imagine you had a multi port device, and assign the stats appropriately.
> > 
> > I didn't see anything in the list that made me think "device stat" but I don't know
> > what several of these do
> 
> Are we exporting port stat when it should be really be device stat in some of the drivers though?
>
> Most vendor drivers do port stats allocation only. Like...
> https://elixir.bootlin.com/linux/v5.13-rc2/source/drivers/infiniband/hw/cxgb4/provider.c#L392
> https://elixir.bootlin.com/linux/v5.13-rc2/source/drivers/infiniband/sw/rxe/rxe_hw_counters.c#L27

Yes they don't have global device counters, presumably because they
only have 1 port.

> However .get_hw_stats callback appears to extract from same set of registers for each port

Most devices should only have port counters

> > If you can confirm that these are all port stats I can delete the device stats in this
> > series.
> 
> So your device and port stats op callback separation feels warranted.

So should I delete the device counters here?

Jason